How are blood banks or transfusion services planning to address the new AABB requirement to have methods to limit and detect bacterial contamination in all platelet components?

A colleague wants to know if others would share how they intend to comply with the new AABB Standard 5.1.5.1 "The blood bank or transfusion service shall have methods to limit and detect bacterial contamination in all platelet components" (when it becomes effective) and the new CAP Transfusion Medicine Checklist, TRM.44955 - Phase I 'Does the laboratory have a system to detect the presence of bacteria in Platelet components?'

The following responses have been received.

1. Dr. Mark Brecher has graciously provided a copy of a draft protocol solution, part of which is shown below. The full protocol is available here as an Acrobat PDF file.

1.0  Introduction

Approximately 1:1000 to 1:2000 platelet units are bacterially contaminated. Post transfusion platelet-associated sepsis is the second most common cause of death associated with transfusion (following ABO-incompatible transfusions). It is estimated that 1 in 50,000 to 1 in 60,000 bags results in septic death. The risk of receiving a bacterially contaminated unit is orders of magnitude greater then the risk of receiving a virally contaminated unit (i.e., HIV, HCV or HBV). In Europe many centers routinely culture platelets.

The bioMérieux, Inc. BacT/ALERT Microbial Detection System (a fully automated blood culture system) to detect and recover seeded microorganisms from platelet blood products. Brecher ME, Means N, Jere CS, Heath D, Rothenberg S, Stutzman LC. Evaluation of the BacT/ALERT 3DÒ Microbial Detection System for platelet bacterial contamination: An analysis of 15 contaminating organisms. Transfusion 2001;41:477-482.

Brecher ME, Heath D, Hay S, Rothenberg S, Stutzman LC. Evaluation of a new generation culture bottle using the BacT/ALERT 3Dâ Microbial Detection System on 9 common contaminating organisms found in platelet components. Transfusion 2002, 42;774-779.

Units would not be held pending the results of the culture due to the short shelf-life of the product. Culture positive units would be re-called, placed in quarantine and be re-cultured. In the case of a transfused unit with a positive culture, the clinicians taking care of the recipient would be notified.

For full details of this draft protocol, please refer to the Acrobat PDF file.

2. Lisa Schaeffer, MT(ASCP), Technical Supervisor, Transfusion Service, and Alan E. Caroe, M.D., Blood Bank Medical Director of York Hospital in York, PA graciously provided the following DRAFT PROCEDURE FOR DIPSTICK TESTING OF PLATELET UNITS

Discussion:
Glucose and pH in all platelet units will be measured using a reagent test strip (Multistix, Bayer Corp.) to screen for the physiologic effects of bacterial contamination. Each individual unit of random and pheresis platelets will be tested with a reagent test strip prior to pooling of the random platelets and prior to issue of the pheresis products.

Platelet products will be considered suspect for bacterial contamination when they fit either one or both of the following criteria:

• Glucose Level less than 250 mg per dL
• pH value of less than 7.0

Random platelet units which are considered to be suspect for bacterial contamination will be discarded without further testing. Apheresis platelets that are considered to be suspect for bacterial contamination using the dipstick methodology will have a confirmatory test done by a Chemistry analyzer only for the analyte in question based on dipstick testing. An aliquot of platelets will be hand carried to Chemistry with a Priority 2 (urgent) request since release for transfusion will be pending. The result of the confirmatory testing will determine the outcome of the apheresis product, using the same criteria as the dipstick screen.

Procedure:
The dipstick testing of each platelet unit will be done by the Transfusion Service, since they have possession of the product immediately prior to pooling and dispensing. Following bag agitation, each platelet tail will be stripped three times and a portion of the platelet tail will be heat-sealed to provide sufficient fluid to make at least two drops. The segment will be cut off from the tail and will be slit to produce drops which will be applied directly to a dipstick in a manner conforming to the Multistix product insert. If a random platelet unit fails the dipstick method, it will be discarded physically and electronically and will not be included in a platelet pool. Any apheresis product that fails the dipstick and fails subsequent confirmatory testing will also be discarded. Those apheresis products that fail the dipstick, but pass the confirmatory testing are transfusable within 4 hours of the intial, dipstick testing. Products held more than 4 hours after a passing test must be retested immediately prior to subsequent release. Note It was decided that upon the commencement of this testing that the current Quality Control method of "Swirling" would no longer be needed and may be discontinued when dipstick testing begins. (Loss of swirling predicts pH less than 6.2. The pH strip should identify all units with a pH of 7 or less.

Quality Control:
Currently, the Urinalysis Department does Quality Control on the Multistix reagent strips daily and with each new lot number. The Blood Bank Manager will determine the feasibility of using the QC test kits from Urinalysis for the daily QC. The QC will be performed and documented daily in the Transfusion Service Department.

ADDENDA Mar. 10, 2003

3. A colleague at a blood center in California reports that they have methods in place to 'limit' bacteria in platelets, and plan to add one or two more. However, if the transfusion services that this blood center supplies wish to 'detect' bacteria in units that the blood center sends to them, the hospitals may proceed, since the blood center does not intend to do this at this time.
   
   
4. A transfusion service medical director in Los Angeles reports that his hospital plans to comply with both the AABB Standard and the CAP Checklist item by purchasing leukocyte-reduced plateletpheresis units from suppliers that implement routine Quality Control culturing of platelets for bacterial contamination. It is anticipated that 'planning' to obtain such platelets will satisfy the phase I CAP Checklist item and that the receipt of these platelets should precede the implementation of the AABB Standard.

ADDENDA Mar. 11, 2003

5. In response to the DRAFT PROCEDURE FOR DIPSTICK TESTING OF PLATELET UNITS (reply #2 above), a colleague in Detroit is of the opinion that it would be prudent that platelet units found unsuitable for transfusion by dipstick testing should be cultured, rather than simply discarded, so that we might gather data on the sensitivity and specificity of this method for detection of bacteria in these components.

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